With the aid of a multipotent stem cell line (FDCP-mix cells) co-cultured with either normal or irradiated Swiss 3T3, cellular interactions between stromal cells and haemopoietic stem cells were studied by electron microscopy and time-lapse video microscopy. When cultured in the presence of interleukin 3 (IL-3) but in the absence ...

The formation of focal contacts by fibroblast-like 3T3 and 9390 cells and endothelial XTH-2 cells was examined with the use of reflection interference contrast microscopy at different cell densities. It was found that cells density-inhibited in growth loose all focal contacts with the substratum. This observation explains the disappearance of ...

125I-labeled angiogenin binds rapidly to the plasma membrane of several cell lines at 37 degrees C (t1/2 less than 1 min) but in comparatively small amounts. Competition with unlabeled angiogenin varies markedly with different cell lines, being most effective in vascular smooth muscle and fibroblast cells. Angiogenin modulates mitogenic stimuli ...

Our laboratory and others have demonstrated that Na+-H+ exchange can be regulated by two different pathways; one that is mediated by an inositol trisphosphate-stimulated increase in intracellular calcium activity, and one that is mediated by an increase in protein kinase C activity. To determine whether one of these pathways is ...

Effects of activin A on cell growth were studied in Balb/c 3T3 cells. When incubated with serum, activin A inhibited serum-induced increase in DNA synthesis in a concentration-dependent manner. Activin A also inhibited serum-induced increase in cell number. When added in quiescent cells, activin A did not affect competence-inducing activity ...

Swiss 3T3 cells were labelled for 36 hours with high levels of 3H-myo-inositol and the radioactivity in nuclear inositol phospholipids was measured. Treatment of cells for 2 minutes, but not for 4 hours, with mitogenic concentrations of insulin-like growth factor I and bombesin caused a slight decrease in PtdIns and ...

Phenol was found to be an acceptable positive control substance for cytotoxicity assays in a new device, the "in vitro pulp chamber" (IVPC). Various concentrations of phenol were used to study its biologic effects on Balb/c 3T3 cells as well as its diffusion characteristics through various thicknesses of dentin disks. ...

Attachment and growth of mouse fibroblast cells on polypeptide derivatives with different wettabilities were studied in the presence or absence of serum proteins. In the presence of serum, a peak level of cell attachment was observed for substrates with a contact angle of around 70 degrees. However, no relationship was ...

Azatyrosine [L-beta-(5-hydroxy-2-pyridyl)-alanine], an antibiotic isolated from Streptomyces chibanensis, inhibited the growth of NIH 3T3 cells transformed by the activated human c-Ha-ras gene but did not significantly inhibit the growth of normal NIH 3T3 cells. Surprisingly, upon treatment with azatyrosine most of the transformed cells apparently became normal. These apparently normal ...

The factors and cellular interactions that influence the commitment of cells to specific neural lineages are not well understood. We have used cultured non-neuronal process-bearing (PB) cells from neonatal rat cerebral cortices as a model to assess the influence of various culture conditions on the determination of cells as either ...

A confluent PtK2 cell sheet was incised in a serum-free culture medium, at 15 min, 2 hr and 24 hr after wounding. The culture media were collected in the same way and used as conditioned media. Unwounded confluent cells were cultured in the conditioned medium for 24 hr. They showed ...

Balb/c 3T3 cells have long been used in cell biological studies. When cells were treated with 2 mM sodium butyrate they became flattened and their nuclei became small relative to the cytoplasm. Electron micrographically, intracellular organellae developed significantly: the number of mitochondria increased and membranous structures, namely the rough-surfaced endoplasmic ...

Valinomycin is a depsipeptide antibiotic that selectively translocates potassium ion across biologic membranes. This drug has been reported to display antitumor effects, but its use has been limited by its extreme toxicity. However, its incorporation into lipid vesicles (liposomes) has resulted in a reduction in toxicity and in the enhancement ...

We investigated the requisites for, and functional consequences of, the relocation to the nucleus of a transforming nonkaryophilic mutant of the simian virus 40 large T antigen (a natural deletion mutant lacking an internal large-T-antigen domain that includes the signal for nuclear transport). Synthetic oligonucleotides were used to obtain gene ...

The gubernaculum testis is the connective tissue organ that causes the testis to descend. How the process of testicular descent is regulated is not fully understood. Current hypotheses postulate that a nonandrogenic fetal testicular factor controls the first phase of descent, that is characterized by growth of the gubernaculum and ...

Genistein inhibited topoisomerase II and I; it increased the enzyme-DNA complex in L1210 cells at 1 micrograms/ml, and interfered with pBR322 DNA relaxation by the enzymes. To test the role of topoisomerase in the transformation by oncogenes, the effect of genistein on the transformation of NIH 3T3 cells by transfection ...

We have prepared a fraction of commercial fetal calf serum whose major component comprises proteins of apparent molecular mass 65-80 kDa. These preparations elicit cell spreading responses in serum-free medium at concentrations similar to those reported for human vitronectin. In addition, we have identified (by a protein blotting technique) the ...

The replica filter technique has been used to isolate variants of Swiss mouse 3T3 cells which produce heparan sulfates with altered levels of sulfation. These changes in the extent of sulfation correlate with alterations in cell morphology, in the organization of cytoskeletal elements, focal contacts, and the extracellular matrix, and ...

Using benzo(a)pyrene (BaP) as a probe for aryl hydrocarbon hydroxylase (AHH) activity, differences in mixed-function oxidase (MFO) activity were observed using microspectrofluorimetry in single living cells during long term treatment with 3-methylcholanthrene (3-MC) or carbaryl. Although these two compounds differ in chemical structure, similar effects were observed in 3T3 cell ...

There is growing evidence that cell shape regulates both proliferation and differentiated gene expression in a variety of cell types. We have explored the relationship between the morphology of articular chondrocytes in culture and the amount and type of proteoglycan they synthesize, using cytochalasin D to induce reversible cell rounding. ...

The interaction of cells with solid surfaces is important in many settings, including the response of tissue to implanted materials. Protein adsorption to the surface plays a critical role in controlling cell interactions with surfaces. However, few comprehensive studies of both cell behavior and protein adsorption in complex protein mixtures ...

The growth rate of spontaneously transformed BALB/3T3 cells is proportional to glutamine concentration between 50 and 400 microM, with little or no growth occurring in less than 50 microM glutamine. By contrast, nontransformed BALB/3T3 cells multiply, although slowly, with as little as 20 microM glutamine. Neither cell type depletes the ...

When highly-purified nuclei of Swiss-mouse 3T3 cells are incubated with [32P]-gamma ATP, radioactivity is incorporated into phosphatidic acid and the two polyphosphoinositol lipids, phosphatidylinositol(4)P and phosphatidylinositol(4,5)P2. If the cells are pre-treated with insulin-like growth factor I, this incorporation into the phospholipids is decreased. The effect is maximal by 2 minutes, ...

Malignantly transformed mouse fibroblasts synthesize and secrete large amounts of major excreted protein (MEP), a 39,000-dalton precursor to an acid protease (cathepsin L). To evaluate the possible role of this protease in the transformed phenotype, we transfected cloned genes for mouse or human MEP into mouse NIH 3T3 cells with ...

A culture of BALB/c 3T3 cells grown in the presence of 40 microM of the ceramide analog compound RV538 (2-decanolyamino-3-morpholino-1-phenylpropanol) for several passages caused a substantial decrease in the level of all glycosphingolipids and an accumulation of ceramide and sphingomyelin. Associated with these chemical changes of sphingolipid composition and metabolism, ...

Cell quiescence resulting from culture of normal human fibroblasts in low serum (0.5%) was associated with a subsequent gradual increase in the expression of the cell-surface glycoprotein VLA-1, and a corresponding decrease in the expression of extracellular matrix adhesion receptors VLA-2 and VLA-3. Quantitation using either flow cytometry or immunoprecipitation ...

To investigate whether resting cells of 3T3 mouse fibroblasts carry out de novo synthesis of deoxyribonucleoside triphosphates, we determined the turnover of the thymidine triphosphate pool of G0 cells obtained by starvation of cultures for platelet-derived growth factor. These cells were contaminated by less than 1% S-phase cells. In the ...

Mitogen (PHA)-induced proliferation of peripheral blood mononuclear cells (PBMC) was reduced by more than 70% 2 h after the haemorrhage of 30% of blood volume. Experiments using isolated macrophages and lymphocytes showed that post-haemorrhage macrophages were functionally normal and that lymphocytes were responsible for the observed haemorrhage-induced depression of proliferative ...

We have previously shown that normal chicken serum (NCS) is able to interfere with the IL 2 promoted incorporation of DNA precursors into T lymphoblasts and that serum derived from autoimmunity prone Obese strain (OS) chickens is deficient in this respect. This "defect in non-specific suppression" has been speculated to ...

Experiments on the introduction of the regulatory subunit of cAMP-dependent protein kinase type II (RII) into NIH 3T3 cells clearly demonstrated its translocation into the nucleus. The labelled protein was incorporated into erythrocyte ghosts and their fusion with the cells was carried out. The dynamics of distribution of the labelled ...

Acidic fibroblast growth factor (aFGF), a polypeptide with a mol. wt of approximately 16,000, is a potent mitogen for a variety of cells and shares 55% amino acid sequence identity with basic FGF. The recent isolation of three new oncogenes which share 35-45% amino acid sequence similarity with the FGFs ...

The rate of attachment of chick embryo fibroblasts (CEF) incubated for 1 h at pH 6 in the absence of serum, was equal to about 90% with 2% of spreading cells. The addition of 1% horse serum (HS) decreased to about 30% the rate of attached cells but increased to ...

The effects of cell density and growth in 10% foetal bovine serum and 10% newborn calf serum on the activity of the enzyme (Na+ + K+)-ATPase were studied in 3T3 and SV3T3 cells. The enzyme activity decreases in 3T3 cells grown in foetal bovine serum as the cells approach confluency ...

We have detected and partially characterized factors that promote the directed migration of mouse epidermal cells in a modified Boyden chamber assay. Smooth muscle cells grown in culture were found to secrete a potent chemoattractant for epidermal cells. This activity was further characterized and compared to the chemotactic activities found ...

At low serum concentrations (3% or less), individual Swiss 3T3 cells display marked heterogeneity in proliferative capacity. Here we show that this heterogeneity arises at extremely high frequency within a clone, often with sister cells showing considerable differences in capacity for further proliferation. The heterogeneity is unlikely to be due ...

The turnover of phospholipids was investigated in quiescent serum-starved Chinese-hamster ovary (CHO-K1) cells stimulated to progress through the cell cycle by the addition of dialysed bovine serum. A variety of radiolabelling techniques were employed to study the rapid effects of serum on phospholipids and later events during G1 and S ...

A method is described for the determination of cellular F-actin content using fluorometry of TRITC-phalloidin at very high dilution. In this case no saturation of all binding sites available is reached, however the staining is highly specific and the specificity is not affected by the preparative procedure as may be ...

A highly active adipogenic agent was identified in an in vitro adipose conversion system. This agent, ADD 4743 (or ADD), was synthesized by Takeda Chemical Industries (Osaka) as a 3-hydroxy derivative of an oral antidiabetic agent, ciglitazone, and has been presumed to be an active metabolite of the latter substance. ...

To evaluate the proteolytic activities of oncogene-transfected 3T3 cells, we have developed a copolymerized substrate electrophoretic assay that permits the detection of picogram quantities of proteases produced by cells in culture. Our assay involves a gelatin substrate copolymerized in a polyacrylamide gel. Purified cell membrane preparations were run on gels ...

Alteration of the growth properties of the established murine fibroblast cell lines NIH 3T3 and 3Y1 was studied in monolayer cultures and in cells suspended in semisolid medium after introduction of a cloned human papillomavirus type 16 (HPV16) DNA. HPV 16 DNA stimulated both cell lines to grow beyond their ...